It is well known that raising the temperature of body tissue tends to reduce blood flow within the tissue. If the temperature is raised by 20-30.degree. C. above normal, blood flow within the tissue is greatly diminished.
In surgical procedures performed on deep-seated body tissues and organs, e.g. the liver, blood loss from severed tissue can be a serious problem. There is an obvious need for a device which can assist in limiting such blood loss and, as indicated above, this can be achieved by means of the application of heat. Widespread heating can be achieved relatively easily, but this is not desirable. Very, localized heating is required in order to minimize damage to surrounding tissues. In liver surgery, local heating of the liver is ideally required in a tissue volume approximately 5 cm long by 2 cm wide by 4 cm deep; this volume is centered on the planned point of incision. Furthermore, it is important for the local elevation of temperature to be achieved quickly just prior to commencing the surgical procedure.